Front-wheel driving mechanism for bicycles



pri 3, 1951 T, SAXER 2,547,600

FRONT WHEEL DRIVING Mr-:cHANrsM Foa BICYCLES Filed Feb. 12,1948

Patented Apr. 3, 1951 FRONT-WHEEL DRIVING MECHANISM FOR BICYCLESl Theodor Saxer, Rorschach, Switzerland Application February 12, 194.8, SeralNo. 7,988 In Switzerland February 12, 1947' (Cl.l 2130-245) 5 Claims;

.top of the fork of the front-wheelof the bicycle inside of which case two handle 'oars are ar- .'ranged which are pivotable in opposite directions and may be fixed in an intermediate position. At the inner ends of the handle bars` are disposed adjacent toothed segments permanently fixed and meshing with spur-gears connected to a driving shaft by means of ratchet and pawl locks and further spur-gears, This driving shaft, arranged between the spur-gears, is coupled toa sprocket wheel laterally arranged outside the gear case and transmitting the force by means of a chain to its mate fixed to the hub of the vehicles front-wheel, whereby direction of rotation remains always the same.

2 vice across the longitudinal axis of the handle bar, and

Fig. 3 is a section taken along line III- III of Fig. 2 and shown on a larger scale.

is shown in Figs. l and 2 the gear case 2- with cover 3 therefore is xed to the shank of the handle bar sections or portions 5 6 which is vertically adjustable along the iront ork tube V in the usual way and rmiy` held in position on saidA iront fork by any known securing means. To this end, Screw-bolts. 4 may be employed engagng. ,Slots provided in the gear case 2. As seen in driving direction the right handle bar 5 is arranged at the right ofthe gear case and the left handle bar 5 at the left of the gear case cover, i. e. the handle bar 5 is xed to the socket extension tube 'la of the gear segment 1 supported in ball bearings. and the handle bar to the socket extension tube 3a of the gear segment 8, also supported by suitable ball bearings. On threaded rod ends 9 and I'Ei are fitted conical sleeves I I, i2 which engage the inner hollow ends of the handle bars which are fixed in a conventional manner to longitudinally slotted ends of To this end, the mechanism is designed in suchy l a way as to allow the handle bars to be readily and easily locked in their intermediate position in order to enable the operator to use them as a one-piece handle bar of the conventional or orthodox type. f

Such a driving unit can be xed to any standard bicycle no modication Whatever being necessary as regards the rigid frame orthe pedal gear.

For disabled cyclists, for instance, lame in one leg and able to use but one of the pedals, the present driving device renders assistance inasmuch as the cyclist will be in a position to drive safer and with more ease. Furthermore with such a driving device the multiple speed gear otherwise used to overcome gradients may be dispensed with, since due to the arms co-operation, effectively more work will be performed.

An embodiment of the present invention is shown on the drawing wherein Fig. l is a fragmentary elevational view of the irontnortion of a bicycle :fr-aine with the front wheel thereof tted with the-'driving device according to lthe invention, j'

Fig. 2 is a horizontal section of the driving devthe socket extension tubes 'ia and 8c, respectively, Due to such fixation the handle bars 5 and 5 can. be turned to assume an intermediate position in, the most convenient way and to be locked therein by the cyclist. In Fig. 1 for instance, such intermediate position oi the handie bars 5, 6. is shown in full lines and in dot and dash lines the position for driving is illustrated, one bar being pulled up and its correspending bar pressed down. AS shown in the 1 drawing the handles are given a socalled anatomical shape vfor the sake of a better grip and not the conventional cylindrical form, Inside the gear case is further arranged a springloaded catch bolt i3 which can be operated by means of a screw knob i3d projecting beyond the casing 2 so as Ato lock the two handle bars 5, 5 in their intermediate position should iront Wheel driving not be required, whereby this catch bolt I3 engages suitable notches of the hub of the gear segments l and 8, respectively.

Inside the gear case 2 at the front portion, two pins I4 and l5 parallel to the handle bars are lodged at some distance from each other. To one of these pins a wheel hub I6 is xed carrying a large toothed rim iic and a smaller toothed rim Ilib. The toothed rim of the gear segment 8 directly meshes with. the gear rim Ilia, Whereas the gear of the Lsmaller gear segment l, Very much smallerin diameter, `meshes with a pinion l1 which in turn meshes with the gear rim |612 of the wheel hub I6. On the cup-shaped portion arranged which, as may be seen on Figs. 2 and 3, together with the wheel hub I6 engages a ratchet pawl lock unit of known design provided with teeth at one of its ends. To the axle or pin I a wheel hub I8 (similar to I6), is fixed to mesh with it. As explained above, a hub portion 2U, which is cup-shaped, is combined with the wheel hub IS to form a ratchet and pawl lock unit. The sleeve also is fitted with teeth 20a at one end. In the middle between the axles I4 and I5 a hollow axle 2I is supported by suitable ball bearings. Projecting beyond the gear case 2 is a sprocket wheel 22 which, by means of a chain 23, acts upon its mate sprocket-24 xed to the axle of the front wheel R. The hollow axle 2| is tted with teeth 2Ia inside the gear case thus meshing with the two hub sleeves I8 and 20.

The aforesaid driving device acts in the following way:

Let it be assumed that the cyclist were driving on the level without making use of the front wheel driving device and the handle bars are locked in their intermediate position by means of the catch bolt I3, thus allowing the two handle bars to be used in the ordinary manner of bicycle operation. If the cyclist wishes to increase the speed or to drive up-hill he will unlock the handle bars 5 and Ii by turning the screw knob I3a so that he can now operate the front wheel driving device in theY following way:

While, for instance, the right leg bears on the pedal urging the same downwards, at the same time the right handle bar is pulled upwards by the right arm of the cyclist; then the left leg will move in upward direction and the left handle bar is urged down by the left hand. These operations will be executed alternately on the right and on the left each after half a revolution of the corresponding crank. Transmission of the motion inside the gear case will take place as follows:

When operating the handle bar section 5, the gear segment I will be rocked and its motion transmitted to the intermediate pinion I1 and from here to the gear rim IEb of smaller diameter on to the wheel center I6. At the same time by urging down the handle bar section 6 the gear segment 3 will be rocked directly acting upon the gear rim Isa of larger diameter. This angular displacement of the gear hub I6, i. e. of its gear rims will be transmitted to the spur gear I9 and the two wheel hubs I8 and I9 by means of the intermediate ratchet and pawl lock unit and the gear 2Ia alternatively urge the hollow axle 2| together with the sprocket wheel 22 fixed to it. The chain 23 transmits these driving forces or impulses to the sprocket wheel 24 and thus to the front Wheel.

When with the subsequent driving impulse the handle bar 5 is being depressed and the handle bar Ii raised, the forces imparted to these bars again will act upon the wheel hub I 6 with the difference, however, that instead of what has just been described, the hub sleeve I 8 will be positively urged by the ratchet and pawl lock unit and the revolving motion thus produced again transmitted to the gear 2 Ia of the hollow axle 2I and from here on to the front wheel R. The sprocket wheel 22, however, will always be rotated in the same direction.

"--l- By this operation, therefore, the alternate up and down motion of the handle bars 5'and `I5 is converted into a continuous revolving motion acting upon the sprocket wheel 22 and drive the front wheel R, whereby the chain 23 1s always exposed to a uniform load and thus kept taut.

The hub of the front wheel is best constructed as a free wheel hub in order to prevent the front wheel from being locked on pushing the bicycle backwards.

The advantage of the described driving device besides of the favorable utilization of the force in the cyclists arms especially consists of the fact that the bicycle of orthodox construction in all its details will not be changed since the driving unit for the front wheel can be readily fixed to any bicycle, whatever. Furthermore, merely spur gears and the chain, the most reliable transmitting element, are made use of instead of bevel gears with their high loss by friction and of delicate transmitting means, such as Bowden or other metallic cables.

Owing to the simplified construction of the locking device according to this invention the handle bars when used as a one-piece bar may be readily locked, and may also be switched for use in the front wheel drive or vice-versa with out any loss of time and in an easy manner.

Instead of using an intermediate pinion II, as shown, power transmission from the gear segment 'I would also be possible by means of a. double gear wheel acting upon the gear rim' Iiia.

It can thus be seen, that there has been provided according to the invention a driving mechanism for front wheels of bicycles and like vehicles having a fork, upon which is positioned a gear casing, two handle bar sections arranged for pivotal movement on said casing, said handle bar sections having inner ends and extending with their outer ends laterally beyond said gear casing, gear means within said casing and operatively connected to said inner ends of said handle bar sections, respectively, said gear means including two pins and a driven shaft below said `handle bar sections and extending from within said casing therewithout, transmission means on said driven shaft for connecting the latter to said front wheel, said pins and said shaft being arranged in parallel relation to each other and to said inner ends of said handle bar sections, said handle bar sections being provided with respective actuating means establishing driving connection with said gear means, and ratchet means ensuring rotation of said driven shaft in one direction only upon movement of saidhandle bars and said actuating means.

` Having thus described the invention, what is claimed as newand desired to be secured by Letters Patent, is:

v 1. A driving mechanism for bicycle front wheels having a fork, comprising a gear casing for position on top of said fork, two handle bar sections arranged for pivotal movement on said casing, said handle bar sections having inner ends and extending with their outer ends laterally beyond said gear casing, gear means within said casing and operatively connected to said inner ends of said handle bar sections, respectively, said gear means including two pins and a driven shaft below said handle bar sections and extending from within said casing therewithout, transmission means on said driven shaft forl connecting the latter to said front wheel, said pins and said shaft being arranged in parallel relation to each other and to said inner ends of said handle bar sections, said handle bar sectionsbeing provided with respective actuating means establishing driving connection with said gear means, and

ratchet means ensuring rotation of said driven shaft in one direction only upon movement of said handle bars and said actuating means.

2. A driving mechanism according to claim 1, including means extending from within said casing therewithout and operable to engage said actuating means of said handle bar sections to block the latter in predetermined position.

3. A driving mechanism according to claim 1, wherein said actuating means form two toothed segments one for each handle bar, one of said segments being smaller in size than the other of said segments.

4. A driving mechanism according to claim 3, wherein one of said gear means on one of said pins is engageable by both said toothed segments.

5. A driving mechanism according to claim 1, wherein said actuating means form two toothed segments one for each handle bar, one of said segments being smaller in size than the other oi.' said segments and, wherein both said segments are provided with tubular extensions, and means coupling said tubular extensions to said handle bars.

THEODOR, SAXER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

